The court chapel of Frederick the Great, King of Prussia, was one of the most important musical institutions of Germany in the mid-18th century. In his service were a number of the most prominent musicians of the time, such as the Benda brothers, the Graun brothers, the keyboard player Carl Philipp Emanuel Bach and the flautist Johann Joachim Quantz. This disc includes music by a lesser-known member of Frederick's chapel, Johann Gottlieb Janitsch.

He was born in Schweidnitz in Silesia (now Swidnica in Poland) and was educated in the bass viol. After having been a law student in Frankfurt an der Oder, where he also played a major role in local musical life, he joined the chapel of Frederick, then still Crown Prince of Prussia, in Ruppin, later Rheinsberg. It is here that he started a series of weekly concerts on Fridays, the Freitagsakademie. It is likely that his chamber music was written for performances during these concerts in which both professional and amateur players participated. When Frederick became King of Prussia and moved his court to Berlin, Janitsch continued his Friday academies there.

The present disc includes four sonatas and an orchestral overture. Although one of the sonatas is called a sonata da chiesa and the other three sonata da camera, there is no real difference between them. They are all scored for three melody instruments and basso continuo and can therefore be ranked among the genre of the quartet, which was considered as the ultimate proof of a composer's mastery of counterpoint. In his treatise Versuch einer Anleitung, die Flöte traversiere zu spielen, Johann Joachim Quantz described the quartet as a sonata with three concertante instruments and a bass line that is "at the same time the touchstone of an authentic contrapuntist and also a real pitfall for a musician lacking experience and compositional skills".

The main composers of quartets were Georg Philipp Telemann, Johann Friedrich Fasch and Janitsch. As the former wrote more than sixty quartets, the liner-notes to the present disc are incorrect in stating that "no other composer of the time wrote so many works in this genre as Janitsch (more than forty works have been preserved)". Quantz judged that Telemann's quartets could be used "as excellent models for this type of music". Janitsch's quartets earned also much praise, for instance from his colleague Johann Wilhelm Hertel, who stated that he "was a fine contrapuntalist, and his quartets are still paragons of their kind."

The three first sonatas performed here come in three movements, in the order slow - fast - fast, which was common in Berlin in the mid-18th century. They are dominated by imitation amongst the instruments. A particularly interesting aspect is the scoring: in some of his quartets Janitsch includes parts for instruments as the oboe d'amore and the viola pomposa. In the sonatas recorded here the instrumentation is more conventional, although a scoring for two transverse flutes and violin was not very common at the time. Also notable is that Janitsch often included a viola part, here in the Sonata in A minor and the Sonata in E flat.

The Sonata in G minor is a special case. It is in four movements, and is scored for flute, two violas and basso continuo. The inclusion of two viola parts lends this piece a rather dark character, which is explained by the fact that Janitsch composed it on the death of his daughter. He called it Quatuor col Melodia ... O Haupt voll etc, referring to the well-known hymn O Haupt voll Blut und Wunden. This hymn is played by the flute in the third movement, with the violas providing the counterpoint and its quotation has given this quartet the title Passion quartet.

Whereas trio sonatas were almost exclusively written for amateurs, quartets were often technically more demanding. That goes for Telemann's quartets, some of which he played with the best French musicians of the time during his stay in Paris in 1737/38; it is also true of Janitsch's quartets, which were probably played during the Friday academies, mostly by professional players. If amateurs were involved, they must have been very skilled, as these quartets are technically challenging. The Sonata in d minor, for instance, includes virtuosic passagework and in the violin part we find episodes with double stopping. The Sonata in E flat is called quatuor con stilo di recitativo. That refers to the opening andante, in which lyrical passages alternate with recitativic episodes.

The disc ends with a piece for orchestra – or. rather, for two orchestras. The ouverture grosso is a hybrid form, a mixture of orchestral suite in the French style - the opening ouverture is in the characteristic binary form, slow - fast, the latter fugal - and the Italian opera overture. There is some similarity with the orchestral works in the oeuvre of Johann Friedrich Fasch, labelled 'overture symphonies' in modern times. In Janitsch' Ouverture grosso in G the overture is followed by a larghetto and a short alla breve, closing with an allegro. As one may expect, Janitsch uses the split of the orchestra in two groups for a musical dialogue between them. However, there are also episodes of a dialogue character within each group, between different sections of the orchestra.

This is not the first recording of quartets by Janitsch. The Canadian label ATMA released three discs recorded by the ensemble Notturna and directed by the oboist Christopher Palameta; as far as I can see, only the Sonata in d minor is included in that series. There are also no duplications with the recording by Epoca Barocca (CPO, 2014). A substantial part of Janitsch's output has been preserved in the archive of the Berlin Singakademie which was discovered in Kiev in 1999 and returned to Berlin two years later. The pieces included here are from the music collection of Sara Levy (1762-1854), a great-aunt of Felix Mendelssohn-Bartholdy. She was an important figure in music life in Berlin, played the harpsichord and was in contact with the two eldest Bach sons, Wilhelm Friedemann and Carl Philipp Emanuel. Around 1818, she gave a large part of her music collection to the library of the Singakademie.

We have every reason to be grateful that she, and later the Singakademie, took care of Janitsch's quartets. These are very fine pieces, which support Hertel's positive assessment. In no way are they inferior to Telemann's quartets. Despite the similarity in form, there is much variety, thanks to the different scorings and the composer's creativity. The performances are technically immaculate and stylistically convincing. I have been quite critical about this ensemble's performances of French music for the theatre ('Comédie et Tragédie'). The players seem to feel much more at home here, which results in much more engaging performances; they show a good understanding of the character of German music, which comes to the fore in their phrasing and articulation as well as their dynamic shading.

Thanks to the music and the performances. this is a compelling disc which every lover of baroque music should add to his collection.